System using a single host to receive and redirect all file access commands for shared data storage device from other hosts on a network

Abstract

Access by multiple hosts, such as computers, to a data storage device by way of a network while maintaining data integrity. In one embodiment, a method for accessing the storage device includes acquiring a resource “lock” that provides exclusive access to one of the hosts at a time. In another embodiment, the file systems of a first and second host provide file system attributes stored in a storage device to provide mutually exclusive access for each host to free blocks of the device. In another embodiment, a networked system contains a first host having exclusive direct access to a storage device over a digital network. A second host requiring access to the storage device communicates with the first host by way of the digital network. File access requests generated by the second host are transferred by a redirection filter driver within the second host to the first host.

1. A networked system for providing access to user data while preserving the data integrity of the user data, comprising:
 a data storage device comprising the user data; 
 a plurality of hosts coupled at a device level to the data storage device by way of a digital network; and 
 a resource lock providing exclusive access to the data storage device to one of the plurality of hosts at a time; 
 wherein commands to the data storage device originating from any one of the plurality of hosts are directed to a first host, the first host redirecting all such commands to the data storage device. 
 
   
   
     2. The networked system of  claim 1 , wherein the resource lock is acquired and released by way of software commands issued over the network by the hosts to the data storage device. 
   
   
     3. The networked system of  claim 1 , wherein the resource lock is implemented entirely in software. 
   
   
     4. The networked system of  claim 1 , wherein the resource lock is released after being held for a predetermined period of time. 
   
   
     5. The networked system of  claim 1 , the data storage device comprising a hard disk drive. 
   
   
     6. The networked system of  claim 1 , the data storage device comprising a writable compact disc drive. 
   
   
     7. The networked system of  claim 1 , the data storage device comprising a writable digital versatile disc drive. 
   
   
     8. The networked system of  claim 1 , the data storage device comprising a magnetic tape drive. 
   
   
     9. The networked system of  claim 1 , wherein at least one of the plurality of hosts comprises a personal computer. 
   
   
     10. The networked system of  claim 1 , wherein at least one of the plurality of hosts comprises a workstation. 
   
   
     11. The networked system of  claim 1 , wherein at least one of the plurality of hosts comprises a personal digital assistant. 
   
   
     12. The networked system of  claim 1 , wherein the digital network is a local area network. 
   
   
     13. The networked system of  claim 1 , wherein the digital network is a wide area network. 
   
   
     14. The networked system of  claim 1 , wherein the digital network is the Internet. 
   
   
     15. A networked system for providing access to user data while preserving the data integrity of the user data, comprising:
 a data storage device comprising the user data; 
 a plurality of hosts coupled at a device level to the data storage device by way of a digital network; 
 a resource lock resident on the storage device and providing exclusive access to the data storage device to one of the plurality of hosts at a time; and 
 filter driver software in each of the plurality of hosts, the filter driver software configured to intercept read and write requests generated within each of the plurality of hosts intended for the data storage device and forward such requests to a single unique host of the plurality of hosts. 
 
   
   
     16. A networked system for providing access to user data while preserving the data integrity of the user data, comprising:
 a data storage device comprising the user data; 
 a first host having exclusive direct access to the data storage device by way of a digital network, the first host comprising a local file system coupled with the data storage device; and 
 a second host coupled to the first host by way of the digital network, the second host comprising a redirection filter driver configured to direct a file access request generated by the second host to the data storage device by way of the local file system of the second host instead of a local file system of the first host. 
 
   
   
     17. The networked system of  claim 16 , wherein:
 the first host further comprises a first network file system coupled with the digital network and the local file system of the first host; and 
 the second host further comprises a second network file system coupled with the digital network and the redirection filter driver of the first host; 
 the second network file system is configured to receive the file access request from the redirection filter and send the file access request to the first network file system; and 
 the first network file system is configured to forward the file access request to the data storage device by way of the local file system of the first host. 
 
   
   
     18. The networked system of  claim 16 , wherein:
 the first host further comprises a first network connection coupled with the digital network and the local file system of the first host; and 
 the second host further comprises a second network connection coupled with the digital network and the redirection filter driver of the first host; 
 the second network connection is configured to receive the file access request from 
 the redirection filter and send the file access request to the first network connection; and 
 the first network connection is configured to forward the file access request to the data storage device by way of the local file system of the first host. 
 
   
   
     19. The networked system of  claim 18 , the network connection comprising a socket connection program. 
   
   
     20. The networked system of  claim 16 , the data storage device comprising a hard disk drive. 
   
   
     21. The networked system of  claim 16 , the data storage device comprising a writable compact disc (CD) drive. 
   
   
     22. The networked system of  claim 16 , the data storage device comprising a writable digital versatile disc (DVD) drive. 
   
   
     23. The networked system of  claim 16 , the data storage device comprising a magnetic tape drive. 
   
   
     24. The networked system of  claim 16 , wherein at least one of the first and second hosts comprises a personal computer. 
   
   
     25. The networked system of  claim 16 , wherein at least one of the first and second hosts comprises a workstation. 
   
   
     26. The networked system of  claim 16 , wherein at least one of the first and second hosts comprises a personal digital assistant (PDA). 
   
   
     27. The networked system of  claim 16 , the digital network comprising a local area network (LAN). 
   
   
     28. The networked system of  claim 16 , the digital network comprising a wide area network (WAN). 
   
   
     29. The networked system of  claim 16 , the digital network comprising the Internet.